{
  "slug": "body-surface-area",
  "title": "Body Surface Area (BSA) Calculator",
  "heading": "Body Surface Area Calculator",
  "category": "fitness-health",
  "url": "https://www.revenuelab.fyi/toolbox/body-surface-area",
  "summary": "BSA by Mosteller, Du Bois, and Haycock formulas.",
  "description": "Body surface area drives chemotherapy dosing, cardiac index, and burn assessment. Compare the three most-used formulas side by side from height and weight.",
  "formula": "Mosteller: √(height cm × weight kg ÷ 3600).",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=body-surface-area",
  "inputs": [
    {
      "id": "cm",
      "label": "Height",
      "kind": "number",
      "hint": null,
      "default": 175,
      "unit": "cm",
      "min": 40,
      "max": null
    },
    {
      "id": "kg",
      "label": "Weight",
      "kind": "number",
      "hint": null,
      "default": 75,
      "unit": "kg",
      "min": 2,
      "max": null
    },
    {
      "id": "co",
      "label": "Cardiac output (optional)",
      "kind": "number",
      "hint": null,
      "default": 5,
      "unit": "L/min",
      "min": 0,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "mosteller",
      "label": "BSA — Mosteller (m²)",
      "format": "decimal",
      "hint": null,
      "primary": true
    },
    {
      "id": "dubois",
      "label": "BSA — Du Bois (m²)",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "haycock",
      "label": "BSA — Haycock (m²)",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "cardiacIndex",
      "label": "Cardiac index (L/min/m²)",
      "format": "decimal",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Height: 175 cm",
      "Weight: 75 kg",
      "Cardiac output (optional): 5 L/min"
    ],
    "outputs": [
      "BSA — Mosteller (m²): 1.909",
      "BSA — Du Bois (m²): 1.903",
      "BSA — Haycock (m²): 1.917",
      "Cardiac index (L/min/m²): 2.62"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter height (cm).",
      "Enter weight (kg).",
      "Enter cardiac output (optional) (L/min).",
      "Read your bsa — mosteller (m²) on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "cm": 105,
        "kg": 45,
        "co": 3
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "cm": 175,
        "kg": 75,
        "co": 5
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "cm": 280,
        "kg": 120,
        "co": 8
      }
    }
  ],
  "limitations": [
    "Population formulas describe averages; individual bodies vary, especially at the extremes of height, age, or muscle mass.",
    "Results do not account for medical conditions, medication, or pregnancy.",
    "Use this as a directional reference, not a diagnosis — talk to a clinician before acting on it."
  ],
  "faq": [
    {
      "q": "Which formula should I use?",
      "a": "Mosteller is the most common in oncology because it's simple and agrees closely with Du Bois across normal ranges."
    },
    {
      "q": "Does BSA hold at extremes?",
      "a": "Less well. In severe obesity the formulas diverge, which is why capped or adjusted dosing exists."
    }
  ],
  "related": [],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Body Surface Area (BSA) Calculator (https://www.revenuelab.fyi/toolbox/body-surface-area)"
}